Timing mechanism



y 1957 R. L MATHEWS 2,792,059

TIMING MECHANISM Filed May 10, 1954 2 Sheets-Sheet l ROBERT L.-MA THE W5 IN V EN TOR.

ATTORNEK May 14, 1957 R, MATHEWS 2,792,059

TIMING MECHANISM 2 Sheets-Sheet 2 Filed May 10, 1954 ROBER r L. MA man's, I N V EN TOR Essen/air A T TORNEK Unit States Patent Ice TIMING MECHANISM Application May 10, 1954, Serial No. 428,442

11 Claims. (Cl. 161 l) The invention relates to a timing mechanism for opening or closing an electrical circuit after a predetermined interval of time has elapsed. The timing mechanism can also be used to control various other non-electrical operations where the automatic actuation of a control member needs to be accomplished after the expiration of a pre-determined time interval.

The timer can, for example, be utilized for controlling the operation of machine tools, dielectric and induction heaters, X-ray and electro-therapeutic equipment, plastic molding machines and pre-heaters, and various other industrial processing equipment or other types of equipment requiring accurately timed interval control.

The device contemplates the use of a control knob for setting the time interval, the timing cycle being initiated by a push button device.

The general object of the invention is to provide a timer having improved mechanism for accomplishing the setting and the subsequent initiation of the timing cycle.

One specific object is to provide a push button device which may be manually operated from the exterior of the timer for initiating the timing cycle and which may be operated by remote control through the medium of an electro-magnet located interiorly of the timer.

Another specific object is to provide a control arm and knob arrangement for coaction with a clutch member to effect the setting of the timer mechanism.

Other objects and advantages of the invention will be apparent from the ensuing specification and the appended drawings in which:

Fig. 1 is a plan view of the timing mechanism;

Fig. 2 is a rear view of the timing mechanism shown in Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary sectional view taken in the same plane as Fig. 3 except that the operating mechanism is also shown in section;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 3;

Fig. 6 is a fragmentary sectional detail view taken on the line 6-6 of Pig. 4 and viewed in a direction opposite to the viewing direction of Figs. 5 and 7; i

Fig. 7 is a fragmentary sectional detail view of the central parts of Fig. 5 showing some of the operating parts slightly shifted in an initial stage of setting movement;

Fig. 8 is a wiring diagram of one form of elective circuit that may be utilized with the timing mechanism;

Fig. 9 shows another form of circuit which may be utilized in remote control operation of the timing mechanisrn; and

Fig. 10 is an example of the use of the timing mechanism in controlling a non-electrical appliance.

In general the device includes a rear plate A, a front plate B spaced from and secured to the rear plate by means of suitable intervening supporting posts, a constant speed electric motor C of the synchronous type, a coun- 2,792,059 Patented May 14-, 1555? tershaft D, suitable gearing E driven by the motor and the control member actuating mechanism F operated through a one way clutch G. In the form of the invention shown an electrical switch H is actuated by the timing mechanism for opening or closing an electrical circuit as desired. A control knob assembly I is utilized for setting the time interval and a push button assembly I initiates the timing cycle.

A series of spacer posts 2 extend between the rear plate A and the front plate B and are secured to each plate by any suitable means. The plates which are shown in circular form could of course be of other shape. A dial 3 is secured to the front face of the front plate 3 as by rivets 61 and has a graduated timing scale (referred to generally by the numeral 4) inscribed in its face in a circular path which is generated from the axis of shaft D. The dial may be made of aluminum foil about .003 thick and having an adhesive on its back surface for securing the dial to the plate B thereby eliminating the rivets 61 if desired. An enclosure band 5 encircles the supporting posts 2 and has radially outwardly projecting tabs 6 and 7 at opposite ends of the band and a bolt 8 projecting through the tabs to secure the opposite ends of the band together. The opposite peripheral margins of the band are provided with sleeves 9 and 1% which may be formed of rubber or some similar material, U-shaped in cross section. The inner peripheral faces 11 and 12 of these strips frictionally engage the supporting posts when the nut is tightened on bolt 8. The timing mechanism is thus totally enclosed between the front and rear plates A and. B and the enclosure hand 5.

The synchronous motor C is secured to the rear plate as by means of screws 15. The motor shaft 16 extends through the rear plate and has a pinion 17 secured thereto for driving the gear 18 which is secured to the driving clutch member 19 which is rotatably journalled on the shaft D. The driven clutch member 20 is rotatably journalled on the sleeve 21 (but could be fixed thereto if desired) between the annular retaining flange 22 and the annular snap ring 23 so that the driven clutch member moves axially of shaft D along with the sleeve 21. clutch teeth 24 and 25 on the respective driving and driven members of the clutch are preferably of the inclined saw tooth type to provide a positive driving connection from driving member 19 to driven member 2%) in a counterclockwise direction as viewed in Figs. 1, 5 and 7.

A pin 26 is anchored to the driven clutch member and projects radially outwardly beyond the circumference thereof and is engageable with the switch lever 27, the under face of which engages the switch button 28 (Figs. 5 and 7) for opening and closing the switch terminals within switch casing 28a as desired.

The push button control includes bracket which has a floor portion 30 integral with the spaced side walls 31 and 32 projecting upwardly from the floor portion. The side walls are mounted between spaced cars 33 and. 34 which are formed on the front plate 3. A pin projects. through the ears and through the side walls of the bracket to provide a fulcrum therefor. A torsion spring 36 encircles the pivot pin and h one terminal 37 abutting the plate B and the opposite terminal 38 (see Fig. 4) overhanging the end of side wall The spring exerts a continuous force on tongue which has its bifurcated end received within the annular groove it in sleeve 21, thereby urging said sleeve and driven clutch member axially along shaft D to close the clutch. The push button 41 which is anchored to the floor of the bracket 29 on the opposite side of the fulcrum pin 35 may be depressed for causing the tongue 39 to move the sleeve 21 in clutch disengaging direction, thereby disengaging the clutch as desired. The dial 3 and the pate B have 3 suitable openings therein at 42 and 43 respectively through which the push button ell projects.

The driven clutch member 20 has a radially outwardly projecting annular flange 44 and an annular groove 45 formed between said flange and the annular shoulder 46 to accommodate the convolutions of a torsion spring 47 one end 48 ot which is secured to the end of arm 49 and the other end of which is secured to pin which is secured to and projects radially outwardly from the annular flange as. The arm 49 has an inwardly bent extension 513. with an lug therein through which the control knob stem 52 projects, the inner end of said stem having a radially outwardly extending annular fiange 53 abutting the inner face of the extension of arm 49, said arm being fixed to the stem 52. so as to rotate therewith whenever the setting knob 54 is rotated. A gasket 55 is interposed between the inner face of plate B and the arm 49 and a spring washer 55 acts against the snap ring 57 and the outer face of plate B to normally urge the setting knob 54 and its operating stem 52 in a direction away from plate l3 thereby providing sufiicient frictional resistance so that when setting knob 54 is rotated to a selected position, the arm 49 will remain in that position although being acted upon by the small amount of torque imposed thereon by spring 47. A pointer 58 is fixed to the setting knob shank 5% and rotates along with the control knob.

Operation In the operation of the timing device with the arrangement of Fig. 8 it will be assumed that the pointer 58 is at zero, whereupon the arm 49 will be in the position as shown in Fig. 5 wherein the side edge 62 thereof will be in engagement with the side edge 63 of the tongue portion 39 of bracket 39. With edge 62 in contact with tongue edge 63 the pointer is at zero and the pin 26 is in engagement with switch lever 27 and switch button 28 is'depressed, thereby opening the switch 66 (see Fig. 8) and the parallel circuits 67 and 68 leading to the motor C and the load L respectively are open (the load represents the appliance which is electrically connected in parallel with the motor circuit), both circuits being opened or closed together depending upon the opening and closing of switch 66. For setting, knob 54 is manually rotated clockwise (viewing Fig. 1) until the pointer 58 is set at the pro-determined setting on the scale 4. In Fig. 1 I have shown a scale which is graduated in seconds and the pointer 58 is set at 75. During setting, the clutch is in normally engaged position and both clutch members remain staionary while the arm 49 is swung away from pin 50 into the position as shown in Fig. 3.

When the pointer is at 150 the side edge 64 of the arm 49 will be in contact with the side edge 65 of the tongue 39 of bracket 3d. Thus it can be seen that the opposite side edges of the bracket tongue serve as stops defining the end limits of the complete arc of travel of arm 49 and pointer 58 about the axis of shaft D.

The next step is to initiate the timing cycle by closing the switch 66 and this is accomplished by depressing the starter button 41 which causes the fork at the end of tongue 39 to move sleeve 21 in a direction toward setting knob 54 axially along shaft D thereby disengaging the clutch, whereupon the torsion spring 47 causes the driven clutch member 29 to be rotated free of clutch member 19 until pin 5% overtakes and engages the edge 62 of arm 49. The pin 59 may have a rubber sleeve 69 telescoped thereon to somewhat dampen noise and shock as the pin 50 strikes the arm 49. The impact with which pin 50 engages arm 49 is slight and is not sufiicient to cause any movement of arm 49 so as to disrupt the setting of arm .9 (the frictional resistance set up by spring washer 56 being sufficient to more'than offset the impact force of pin 50 engaging arm 49). The moment pin 26 commences to move away from switch lever 27, the switch button 28 moves outwardly thereby immediately closing the switch 66 and energizing the circuits 67 and 68. Thus the timing cycle is commenced and the motor C through gearing E drives the clutch member 19 which in turn drives the driven clutch member 243 (after starter button 41 is depressed to close switch 65, it is immediately released and torsion spring 36 thereby immediately effects a re-engagement of the clutch). The driven clutch member is thus rotated counter clockwise viewing Fig. 5 and pin 26 returns toward the switch lever 27. 0n the seventy-fifth second following commencement of the timing cycle the pin 26 again engages lever 27 thereby depressing switch button 23, opening the switch 65, and shutting off the motor C and the load L. The arm 49, however, remains in the position as originally set with the pointer 53 pointing at 75 on the dial scale and if a second timing cycle of 75 seconds is desired, it is not necessary to re-set the control knob 54, however it is necessary to again depress the starter button 41 to close switch and rte-commence the 75 second timing cycle. This operation can be repeated as many times as desired before resetting the knob 54, to a new position on the dial. After the timing cycle has been completed and pin 26 engages lever 2'7 thereby opening switch 66, the timing mechanism remains in this condition with the motor C and the load L shut off until the starter button 41 is again depressed to initiate a new timing cycle.

In the operation of the timing mechanism wherein a remote control device is utilized to close switch 6-5 and thereby initiate the timing cycle, I have shown one arrangement for accomplishing this remote control type of operation in Fig. 9. In this arrangement the motor circuit and the load circuit @711 and 68:: respectively are also connected in parallel so that when the switch is opened, both the motor C and the load L are shut off. Viewing Fig. 3 it will be noted that a magnetic coil 7% is fastened to the rear plate A and the end face 72 of the core is disposed adjacent the under-surface '72 of bracket 3t), said bracket functioning in the manner of an armature, being drawn into contact with the end face 71 of the core whenever the electro-rnagnet is energized. The switch 73 is of the type in which tie switch arm 74 when manually brought into contact with the terminal 75 closes the circuit 7s momentarily until the switch arm 74 is released, then a spring 77 may be employed to immediately open the switch 73 when the switch arm is released. When the switch 73 is momentarily closed, the electro-magnet "7% is energized thereby causing the armature 72 to be attracted against the core 71 thereby disengaging the clutch G and permitting rotation of the driven clutch member until pin 50 engages arm 49, the initial rotation of the driven clutch member causing pin 26 to move away from switch lever 27 thereby closing the switch 66 and initiating the timing cycle. The switch as of course remains closed during the operation of the timing cycle even though switch 73 is open and the electro-magnet becomes deenergized. The switch 73 may be located at any station remote from the timing mechanism and the timing cycle can be initiated as quickly as when the starter button 41 is manually depressed as has been previously fully explained.

In the arrangement as shown in Fig. 10 the timing mechanism is being utilized to operate a non-electrical control member in the form of a valve 30 which may be incorporated in a fluid line indicated generally by the numeral 81. The dial scale 4 is graduated in gallons instead of seconds. When the switch 66 is opened, the valve 8% is normally closed against the valve seat 32 due to the action of compression spring 83 acting against a collar 84 to normally urge the valve in valve closing direction. The armature 85 of a solenoid may be connected to the collar 84 and whenever the solenoid is energized, the armature 85 will move the valve 89 into the valve opening position as shown in dotted lines in Fig. 10. In this arrangement I have shown the remote control operation for initiation of the timing cycle wherein the switch 73 is first closed in order to energize the electromagnet 70 and thereby efiect disengagement of clutch G and the consequent closing of switch 66 whereby to initiate the timing cycle. The valve 80 will, of course, remain in open position during the period of expiration of the timing cycle and when the pin 26 engages the lever 27, thereby opening the switch 6, then the solenoid will be de-energized and the spring 83 will close the valve thereby cutting oif the fluid flow in the conduit 87. The valve of course remains closed until a subsequent timing is initiated. In the arrangement as shown in Fig. I have shown the gear 18 as being directly driven by a Worm 83 which may in turn be driven by a shaft rotated by the metering device 89. The meter 89 is driven by the flow of the fluid from the reservoir 91 through the meter and thence out through conduit 90. When valve 80 is closed upon completion of the timing cycle, the meter stops running and consequently stops the rotation of the clutch G.

It will be understood that the timing cycle may be predicated upon any one of several units of measure such as time (seconds, minutes, etc.) and volumetric quantity (pints, quarts, gallons, etc.) or combinations of time and another unit of measure and as weight (ounces, pounds, etc.) wherein the dial scale would be calibrated in weight units.

I claim:

1. A timer for mechanically and automatically actuating a control member after lapse of a pro-selected time interval comprising: a housing including spaced front and rear supporting walls; a shaft positioned within the housing and mounted in the rear wall, driving and driven clutch members both rotatably mounted on the shaft, the driven member being shiftable axially with reference to the driving member; means yieldingly urging the driven member into clutching engagement with the driving member; clutch release means including a starter part manually engageable exteriorly of the housing, for disengaging the driven member from the driving member, overcoming said yielding means; a setting actuator in front of the housing having a hub projecting through and rotatable in the front supporting wall; an arm secured to said hub within the housing, projecting parallel to the clutch axis, and overhanging the driven member; a torsion spring acting between said arm and driven member and operable, upon disengagement of the driven member from the driving member, to rotate the driven member in a setting movement following a prior setting movement of the setting actuator; a projection on the driven part, engageable with said arm to limit the setting movement of said driven part to correspond to that of the setting actuator; a normally operable control unit within the housing having an actuator part for rendering it inoperative; a second projection on said driven member, engageable with said control actuator part to hold it in a position rendering said control inoperative when said driven member is in a zero position, and releasing said control actuator part for rendering said control unit operative when setting movement of said driven member occurs; a timing motor having a driving connection with said driving member and operable for transmitting through said driving member to said driven member, return movement of said driven member back to the zero position, over a time interval proportional to the setting, whereby to cause said second projection to reengage said control actuator part and thereby to render said control unit again inoperative at the end of said time interval; and means for starting and stopping said motor when said control unit is rendered operative and inoperative respectively.

2. A timer as defined in claim 1, wherein said setting actuator hub includes a bushing portion receiving and rotatable on the forward end of said shaft, and providing a mounting for said forward end.

3. A timer for mechanically and automatically actuating a control member after lapse of a pro-selected time interval comprising: a housing including spaced front and rear supporting walls; supporting means; driving and driven clutch members and a setting actuator all rotatably mounted in said supporting means on a common axis, said setting actuator having a crank arm projecting to a point radially outward of the periphery of said driven member, said driven member being shiftable axially with reference to said driving member for clutching and declutching said members; means yieldingly urging said driven clutch member normally into clutching engagement with the driving member; means including a manually operable starter part for shifting said driven member to a declutched position, overcoming said yielding means; a torsion spring yieldingly acting between said arm and said driven member and operable to rotate the latter, when declutched, in a setting movement following a prior setting movement of the setting actuator; a projection on the driven part, engageable with said arm to limit the setting movement of said driven part to correspond to that of the setting actuator; a normally operable control unit having an actuator part for rendering it inoperative; a second projection on said driven member, engageable with said control actuator part to hold it in a position rendering said control inoperative when said driven member is in a zero position, and releasing said control actuator part for rendering said control unit operative when setting movement of said driven member occurs; a

timing motor having a driving connection with said driving member and operable for transmitting through said driving member to said driven member, return movement of said driven member back to the zero position over a time interval proportional to the setting, whereby to cause said second projection to reengage said control actuator part and thereby to render said control unit again inoperative at the end or" said time interval; and means for starting and stopping said motor when said control unit is rendered operative and inoperative respectively.-

4. A timer for mechanically and automatically actuating a control member after lapse of a preselected time interval comprising: a housing including spaced front and rear supporting walls; supporting means; driving and driven clutch members and a setting actuator all rotatably mounted in said supporting means on a common axis, said setting actuator having a crank arm projecting to a point radially outward of the periphery of said driven member, one of said clutch members being mounted for axial shifting movement for clutching and declutching it with respect to the other clutch members; means yieldingly urging the shiftable clutch member toward the other clutch member for normally eifecting clutching engagement; means including a manually operable starter part for moving said shiftable clutch member to declutched position, overcoming said yielding means; a torsion spring yieldingly acting between said arm and said driven member and operable to rotate the latter, when declutched, in a setting movement following a prior setting movement of the setting actuator; a projection on the driven part, engageable with said arm to limit the setting movement of said driven part to correspond to that of the setting actuator; a normally operable control unit having an actuator part for rendering it inoperative; a second projection on said driven member, engageable with said control actuator part to hold it in a position rendering said control inoperative when said driven member is in a Zero position, and releasing said control actuator part for rendering said control unit operative when setting movement of said driven member occurs; a timing motor having a driving connection with said driving member and operable for transmitting through said driving member to said driven member, a return movement of said driven member back to the zero position over a time interval proportional to the setting, whereby to cause said second projection to reengage said control actuator part and thereby to render said control unit again inoperative at the end of said time interval; and means for starting and stopping said motor when said control'unit is rendered operative and inoperative respectively.

5. A timer as defined in claim 4, wherein said motor is an electric motor, wherein said control unit is a normally closed switch, and wherein said switch is connected to said motor to energize the same when closed and is also operable to control an external circuit.

6. A timer as defined in claim 4, wherein said first mentioned projection consists of a pin anchored in and projecting radially from said driven member, and a sleeve of cushioning material surrounding said pin and constituting a buffer for absorbing the shock of contact with said arm when the two come together 7. A timer as defined in claim 4, wherein said driven member has a broad, shallow annular peripheral groove, and wherein said torsion spring is a coil spring having a coil body retained within said groove and an end part projecting outwardly therefrom and engaged with said arm.

8. A timer for mechanically and automatically actuating a control member after lapse of a pre-selected time interval comprising: a housing including spaced front and rear supporting walls; driving and driven clutch members coaxially journalled within the housing with the driving member disposed near the rear wall in an axially fixed position and the driven member axially shiftable for clutching and declutching; a setting knob in front of the housing having a hub extending through and journalled in the front wall coaxial with said clutch elements; a lever of L-shape secured to the inner end of said hub and including a setting arm overhanging said driven member; a coil spring acting yieldingly between said arm and driven element and wound by the setting rotation of the knob while said driven member is clutched to the driving member and thereby held against rotation; means including a manually operable starter button projecting through said front wall, for declutching the driven member from the driving member when the button is pressed, thereby freeing said driven member for rotation under the pull of said spring in a setting movement following the setting movement of said knob; a first projection on said driven member, engageable with said setting arm to limit the setting movement of said driven element to correspond to that of the knob; a unidirectional electric timing motor; gearing disposed between said driving member and said rear wall and providing a driving connection through which said motorrwill drive said driven element through said driving element, in a direction to return the parts from set to zero position, said first projection being yieldingly biased toward engagement with said setting arm by the pull of said coil spring and thus effecting setting movement of the driven member when the latter is declutched from the driving member; a normally closed switch in said housing, having an actuator lever; a second projection on said driven element, engageable with said lever and moving it to a position opening said switch when the driven element is at zero setting; and connections from said switch to said motor for energizing said motor for rotation during the return of the parts to the zero position, said motor being deenergized upon engagement of said switch lever by said second projection when the parts arrive at the Zero position, whereby the return movement is arrested at the zero position.

9. A timer as defined in claim 8, including a stop against which said arm engages upon return to the zero position, whereby the zero position for the setting knob is positively and accurately determined.

10. A timer as defined in claim 8, wherein said declutching means includes a lever within the casing, having said starter button attached to one end and having at its other end a fork engaging said driven element for transmitting axial shifting movement thereto, and means pivotally connecting said declutching lever to said front wall, said yielding clutch engaging means acting between said front Wall and said declutching lever.

11. A timer as defined in claim 8, wherein said declutching means includes a lever within the casing having said starter button attached to one end and having at its other end a fork engaging said driven element for transmitting axial shifting movement thereto, and means piv otally connecting said declutching lever to said front wall, said yielding clutch engaging means acting between said front wall and said declutching lever, said declutching lever having a part thereof positioned to be engaged by said setting arm and functioning as a stop to positively and accurately limit the return movement of the setting knob at the zero position.

References Cited in the file of this patent UNITED STATES PATENTS 2,644,518 Hertrich July 7, 1953 ma -i 

